The present invention is directed to a dental handpiece which contains two handpiece parts that are axially connectable to one another by means for latching or a catch mechanism. These handpiece parts each have surfaces at the connection formed by the joint therebetween which reside correspondingly opposite of one another in the connected condition. One of the parts is a gripping part which is connectable to a supply hose and the other part is a head part which is removably held at the free end of the gripping part. The head part contains a head housing for acceptance of a tool and a neck portion extending from the housing and having a guide shank for the acceptance of the drive shaft for the driving of the tool. In addition, the handpiece will have agent lines for water and air and means for conducting light with at least the means for conducting light emerging from the gripping part at the end of the gripping part facing the head part.
A dental handpiece is disclosed in U.S. Pat. No. 4,348,180, whose disclosure is incorporated by reference, and which patent was based on the European application resulting in European Pat. No. 0,029,862. This handpiece has a head part which contains a catch mechanism in the immediate proximity of the head housing. This catch mechanism includes a cylindrical outside sleeve which is deformable by pressing on both sides and has longitudinally extending catch noses on the free end of the sleeve which will engage correspondingly constructed notches or recesses in the gripping part when the head part is plugged onto the gripping part.
The outside sleeve, which serves as an actuation element, takes up a relatively large area in the immediate proximity of the head housing so that it becomes difficult to allow light and under given conditions other agents to emerge, such as at the end of the gripping part, so that the agents can be optimumly utilized at the preparation location. The latter is of particular significance for light because in order to avoid heavy shadows and light losses, one would like to have the light exit end approach as close as possible to the head housing and extend relative steeply there so that the end of the light conduit extends approximately parallel to the tool axis. In order to achieve this in the known handpiece, the light conductor would have to be conducted through the relatively long neck part of the head part and this means an additional connection in the light conductor. Since light transmission losses are associated with each connection of the light conductor, it is desirable to avoid conducting light in the neck part.